PIC12LC509A-04I/SN - 8-bit 4MHz OTP MCU, 1.5KB | Microchip
MPN: PIC12LC509A-04I/SN ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.42 | $1.42 |
| 10 | $1.25 | $12.50 |
| 100 | $1.08 | $108.00 |
| 500 | $0.92 | $460.00 |
| 1,000 | $0.79 | $790.00 |
PIC12LC509A-04I/SN Overview
An 8-bit microcontroller (MCU) is a small, self-contained computer-on-a-chip that integrates a CPU, memory (ROM/RAM), and peripheral I/O into a single IC. The PIC12C family sits within Microchip's PIC microcontroller hierarchy: PIC12C -> PIC microcontroller -> 8-bit MCU -> microcontroller -> embedded processor -> semiconductor. These MCUs target applications that require deterministic real-time response, low power, and minimal BOM cost in compact packages.
Key features include 5 general-purpose I/O pins, an 8-bit real-time clock/counter (TMR0) with programmable prescaler, Power-On Reset (POR), Device Reset Timer (DRT), Watchdog Timer (WDT) with dedicated on-chip RC oscillator, programmable code protection, and 1,000,000 erase/write cycle endurance. The 33 single-word instruction RISC architecture simplifies code development while the CMOS OTP process minimises die area and cost.
Architecturally, the PIC12LC509A uses a Harvard structure with separate program and data paths, a 12-bit instruction word (vs 14-bit for PIC12F), and a 2-level deep hardware stack. The 'LC' prefix denotes the wide-voltage 2.5V-5.5V variant, while '04' specifies the 4MHz oscillator, and 'I' denotes the industrial temperature grade. The 'SN' suffix identifies the 8-pin SOIC package.
Typical applications include appliance control, sensor conditioning, LED driving, low-cost consumer electronics, automotive body modules, and battery-powered IoT edge devices. The 8-pin form factor with 5 I/O is well suited to space-constrained designs.
When designing, ensure your programmer supports the PIC12C OTP family (e.g. PICkit 2/3, MPLAB ICD) and configure CONFIG register bits correctly. OTP parts require one-pass programming; use PIC12C509A (EPROM window) or PIC12F509 (Flash) if in-circuit reprogrammability is needed.
This page synthesises distributor pricing, verified drop-in alternatives from the PIC12C/12F family, and practical design notes not found in the bare manufacturer datasheet.
Drop-in alternatives for PIC12LC509A-04I/SN — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with PIC12LC509A-04I/SN (same form factor and footprint) — differing in Core Architecture, I/O Pins, Timers, Instruction Set, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC12LC509A-04/SN
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12LC509A-04I/SM
✅ Drop-In✓ In Stock
$0.71 / Unit
View Datasheet →PIC12C509A-04I/SN
✅ Drop-In✓ In Stock
$0.92 / Unit
View Datasheet →PIC12C508A-04I/SN
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12F509-I/SN
✅ Drop-In✓ In Stock
$0.71 / Unit
View Datasheet →PIC12LC509A-04I/SN Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit Microcontroller (MCU) |
| Series | PIC12C |
| Core Architecture | PIC (RISC, 12-bit instruction word) |
| Program Memory | 1.5 KB (1K x 12) OTP |
| RAM | 41 bytes |
| CPU Speed | 4 MHz |
| Instruction Execution Time | 200 ns at 5V |
| Supply Voltage (Vdd) | 2.5 V to 5.5 V |
| Operating Temperature | -40C to +85C (Industrial) |
| I/O Pins | 5 |
| Timers | 1 x 8-bit (TMR0) with programmable prescaler |
| Watchdog Timer (WDT) | Yes, with dedicated on-chip RC oscillator |
| Power-On Reset (POR) | Yes |
| Device Reset Timer (DRT) | Yes |
| Code Protection | Programmable |
| Instruction Set | 33 single-word instructions |
| Package | 8-pin SOIC (SN) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead-Free | Yes |
PIC12LC509A-04I/SN Pin Configuration
| Pin 1 | GP5/OSC1/CLKIN — GPIO bit 5 / Crystal oscillator pin 1 / External clock input |
| Pin 2 | GP4/OSC2/CLKOUT — GPIO bit 4 / Crystal oscillator pin 2 / Clock output |
| Pin 3 | GP3/MCLR/Vpp — GPIO bit 3 (input only) / Master Clear reset / Programming voltage |
| Pin 4 | GP2/T0CKI — GPIO bit 2 / Timer 0 clock input |
| Pin 5 | GP1 — GPIO bit 1 |
| Pin 6 | GP0 — GPIO bit 0 |
| Pin 7 | Vss — Ground reference |
| Pin 8 | Vdd — Positive supply voltage (2.5V to 5.5V) |
Typical Applications
PIC12LC509A-04I/SN is suitable for 6 applications: Battery-Powered IoT Edge Sensor Node, Automotive Body Module Lighting Control, Consumer Appliance User Interface Controller, Industrial Sensor Signal Conditioning, Smart Home Wireless Remote Control, Educational Microcontroller Teaching Platform.
Battery-Powered IoT Edge Sensor Node
The PIC12LC509A-04I/SN fits low-cost wireless sensor endpoints where its 2.5V-5.5V wide-voltage range allows direct operation from a single 3V coin cell down to end-of-life. Its 4MHz core executes wake-up sampling, ADC read (via external ADC), and sub-second transmit cycles while consuming microamp quiescent current in sleep. The 5 GPIO are sufficient to drive a digital sensor, indicator LED, and a sleep/wake interrupt line. With OTP cost under $0.80 at qty 1000, the part enables sub-$2 BOM nodes for throwaway asset tracking tags or smart-farming moisture probes where Flash reprogrammability is not required post-deployment.
Recommended
Automotive Body Module Lighting Control
The PIC12LC509A-04I/SN is well suited to non-safety automotive body modules such as interior LED dimming, ambient lighting fade controllers, and rear-chassis courtesy lamps. The -40C to +85C industrial temp range covers cabin environments, and the 5 GPIO can directly drive N-MOSFET gate inputs or low-side LED strings up to 25mA per pin. The on-chip Watchdog Timer with dedicated RC oscillator provides the reset supervision that automotive OEMs require even for non-safety body modules. The PIC RISC architecture delivers deterministic 200ns instruction cycles, ensuring flicker-free PWM generation for LED current control at automotive 12V bus transients.
Recommended
Consumer Appliance User Interface Controller
The PIC12LC509A-04I/SN is widely used as the tactile-button and 7-segment display controller in low-end white goods such as rice cookers, microwave ovens, and small kitchen appliances. Its 33 single-word RISC instructions simplify code review for IEC 60730 Class B safety software, and 1.5KB OTP easily fits state-machine UI logic, beep patterns, and timer counters. The Device Reset Timer and Power-On Reset ensure clean startup after brownouts common on inductive motor loads sharing the AC mains. The 8-pin SOIC with 5 GPIO is ideal for minimalist front-panel PCBs with 3-4 buttons plus a single buzzer or LED pair.
Recommended
Industrial Sensor Signal Conditioning
In industrial 4-20mA loop-powered transmitters and binary threshold detectors, the PIC12LC509A-04I/SN provides the HART-friendly micro-controller or simple comparator-replacement logic. Its 2.5V minimum supply allows operation from loop-derived 3.3V rails. The Watchdog Timer is mandatory for IEC 61508 SIL-1 sensor SIL loops, and the programmable code protection prevents unauthorised firmware cloning by sensor competitors. With 5 GPIO, designers can drive a HART modem enable line, an open-drain fault output, and a 1-Wire EEPROM for calibration constants. The 4MHz core handles polynomial CRC and HART preamble generation without a DSP.
Recommended
Smart Home Wireless Remote Control
Battery-powered remote controls for ceiling fans, blinds, RGB lighting strips, and HVAC zones are a classic PIC12LC509A-04I/SN application. Its wide-voltage range tolerates 2xAAA battery discharge from 3.0V fresh to 2.0V end-of-life. The 4MHz core wakes, scans a 3x4 button matrix via 5 GPIO using a Charlieplexing scheme, encodes the keystroke into a sub-GHz or infrared OOK protocol, and returns to sleep. Total active time per button press is typically under 5ms, yielding multi-year battery life. The OTP cost structure enables sub-$3 retail price points for high-volume consumer remotes.
Recommended
Educational Microcontroller Teaching Platform
Universities and technical colleges use the PIC12LC509A-04I/SN as a low-cost introduction to embedded programming because the 33-instruction RISC set can be taught in a single lab session. The 1.5KB OTP forces disciplined code size, teaching students to optimise state machines and bit-banged interfaces. The PICkit 2/3 and MPLAB X IDE programmer support is mature and freely available. The 8-SOIC package fits on a standard 0.1-inch-pitch breakout board for breadboarding experiments. Each student can own multiple parts at under $1.50 unit cost, eliminating shared-lab bottlenecks for GPIO, timer, and Watchdog exercises.
Recommended
Recommended Products Summary
Engineering reference data for PIC12LC509A-04I/SN — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12LC509A-04/SN | PIC12LC509A-04I/P | PIC12LC509A-04I/SM | PIC12C509A-04I/SN | PIC12C508A-04I/SN | PIC12F509-I/SN |
|---|---|---|---|---|---|---|---|
| Package | 8-SOIC (SN) | 8-SOIC (SN) - same | 8-PDIP - different | 8-SOIC (SM 208mil) - same footprint, wider body | 8-SOIC (SN) - same | 8-SOIC (SN) - same | 8-SOIC (SN) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB OTP | 768 B OTP (-49%) | 1.5 KB Flash (vs OTP) |
| CPU Speed | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Supply Voltage (Vdd) | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 3.0 V to 5.5 V (-10%) | 3.0 V to 5.5 V (-10%) | 2.0 V to 5.5 V (+10%) |
| Operating Temperature | -40C to +85C (Industrial) | 0C to +70C (Commercial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) |
| Memory Type | OTP | OTP | OTP | OTP | OTP | OTP | Flash |
| Instruction Word Width | 12-bit | 12-bit | 12-bit | 12-bit | 12-bit | 12-bit | 14-bit (code recompile required) |
Key Differentiators
- Wide-voltage 2.5V-5.5V operation in the same SOIC-8 footprint (vs PIC12C509A-04I/SN)
- Lowest unit cost in the PIC12C family at sub-$0.80 qty 1000 (vs PIC12F509-I/SN)
- Industrial -40C to +85C temperature grade included (vs PIC12LC509A-04/SN)
Design Notes
The PIC12LC509A-04I/SN operates from 2.5V to 5.5V; a 100nF decoupling capacitor must be placed within 5mm of the Vdd pin (pin 8) with a wide ground return to pin 7 (Vss). For battery applications drawing below 3.0V, the 'LC' prefix is mandatory - the standard PIC12C509A will not start below 3.0V. Add a 10uF bulk capacitor on the Vdd rail if the source impedance (e.g. coin cell) exceeds 10 ohms at 4MHz to prevent brown-out during GPIO transitions.
Pin 3 (GP3/MCLR/Vpp) is input-only on the PIC12LC509A - attempting to drive it as an output will not damage the part but will read back as '0'. The MCLR function is enabled by the CONFIG register bit MCLRE; if MCLRE = OFF, pin 3 becomes a digital input only and the internal POR provides reset. For programming, Vpp (typically 13V for OTP) must be applied to pin 3 even when MCLRE = OFF during ICSP.
When using an external crystal or resonator on pins 1 (OSC1) and 2 (OSC2), keep the crystal traces short (<10mm) and surround them with a ground pour to reduce EMI crosstalk onto the GP0/GP1 lines. For internal RC oscillator mode (factory default for the '04' speed grade), float pins 1 and 2 or use them as GPIO5/4 with the TRIS register. The OSC2 pin can drive a peripheral as CLKOUT only if the CONFIG bit CLKOUTEN is set.
The 4MHz internal oscillator is factory-trimmed to within +/-1% at 5V/25C; expect +/-2% drift across -40C to +85C and +/-5% drift at 2.5V. For UART or infrared protocols requiring better than +/-2% baud accuracy, calibrate the OSCCAL register against a precision reference during factory test and store the calibration value in the last available OTP location. Software UART bit-banging can tolerate +/-3% for short packets under 8 bytes.
Compliance Information
RoHS and lead-free per Microchip product page. AEC-Q100 not qualified (industrial grade, not automotive-grade). Conflict-minerals declaration compliant per Microchip CMRT.
